Intel SRCU32 - RAID Controller, User Manual

Page: 139 / 182

Storage Console Plus 139
The SCSI Parameter/Initialize
The SCSI parameters configure a physical drive (especially its performance). By changing the
SCSI parameters, you can:
•
Set the Synchronous Transfer Rate terms_sync_transfer
•
Change the Settings of the Hard Drive Cache terms_cache_settings
•
Enable or Disable the Disconnect Feature terms_disconnect
•
Enable or Disable the Tagged Queues terms_tagged_queues
WARNING
By changing these parameters on a new hard disk or a hard disk that has been connected to a
non-compatible RAID controller, the hard disk will be initialized terms_initialization and all data
on this hard disk will be lost.
You can access the change SCSI Parameters / Initialize menu by clicking the right mouse button on
a physical drive in the Physical Drives Windows
view_physical_conf
(View > Physical
Configuration).
Synchronous Transfer
Different to the older asynchronous transfer mode, synchronous transfer offers higher transfer rates
on the SCSI bus. The maximum synchronous data transfer rate depends on the width of the SCSI
bus (8 bit narrow SCSI, 16 bit wide SCSI) and the frequency of the signals on the SCSI bus
(10 MHz for Fast SCSI, 20 MHz for Ultra SCSI and 40 MHz for Ultra2 SCSI and Ultra160 SCSI).
The maximum data transfer rates are shown in the table below.
Table 23. Data Transfer Rates
Narrow SCSI
(8 Bit)
Wide SCSI
(16 Bit)
Fast SCSI 10 MB/s 20 MB/s
Ultra SCSI 20 MB/s 40 MB/s
Ultra2 SCSI - 80 MB/s*
Ultra160 - 160 MB/s*
* (LVD SCSI (low voltage differential) only)
✏ ✏ ✏ ✏
NOTE
The maximum synchronous data transfer rate between a SCSI device and the Intel RAID Controller
SRCU32 can be limited. This limitation may become necessary if a particular SCSI cabling does
not allow the maximum rate the controller and the drive could achieve. Adjust the synchronous
transfer rate in the SCSI parameters / Initialize menu pdisk_parameters.